Writer-director Pete Docter says the parents play a crucial role since Riley is seen through their eyes.

"I started out doing a film about growing up, but it turned out it's a film about me watching my kids grow up,'' says Docter, 46, and the father of an 18-year-old son and a 16-year-old daughter. "These parents are realizing that their kid is changing. That's difficult. But it is a part of life."

Life for Riley is made all the more difficult since Dad has moved the family from the Midwest to work on a start-up company in San Francisco. Meanwhile, upbeat and hip Mom is the emotional center of the family.

"These guys are the pillars on both sides," says Docter. "They are pivotal parts, knowing how joyful this kid Riley used to be and the young woman she's changing into."

So while Riley's mind is full of out-there comedic characters (particularly Joy), the parents are more "rooted in reality and very truthful," says Docter. "Both of those actors do that very well."

Inside Out takes viewers inside the mind of all three human characters. Dad's emotions have Headquarters like a Norad missile defense site and have mustaches. Very male. Meanwhile, Mom's Headquarters features emotions wearing her red glasses and who engage in civil discussion à la The View.

"There's our world which we're conscientious of and looking at. So we're driving, eating dinner, whatever. And inside our head there's this whole rich internal dialogue and world no one else knows about," says Docter. "This film gets you inside each character's heads."

Even everyday moments expand comically as we see each person's inner dialogue and then what comes out of their mouths.

"We're intercutting to show what's going on inside each of their heads behind the scenes," says Docter. "What seems like a simple family dinner is actually fraught with all sorts of emotional angst and drama."